TY - JOUR
T1 - Impact of myocardial fiber orientation on lesions created by a novel heated saline-enhanced radiofrequency needle-tip catheter
T2 - An MRI lesion validation study
AU - Suzuki, Atsushi
AU - Lehmann, H. Immo
AU - Wang, Songyun
AU - Monahan, Kristi H.
AU - Parker, Kay D.
AU - Rettmann, Maryam E.
AU - Curley, Michael G.
AU - Packer, Douglas L.
N1 - Funding Information:
Funding sources: This study was funded by Thermedical. Dr Packer's work is funded in part by a clinician investigator award from the Mayo Foundation.Disclosures: Dr Packer reported receiving grants from the National Institutes of Health (NIH)/National Heart, Lung, and Blood Institute (NHLBI), St Jude Medical Corporation and Foundation, Biosense Webster Inc, Medtronic Inc, and Boston Scientific Corp during the conduct of the study; receiving grants from Abbott, Biosense Webster Inc, Boston Scientific Corp, CardioFocus, Medtronic Inc, St Jude Medical, CardioInsight, NIH, Siemens, Thermedical, Endosense, Robertson Foundation, and Hansen Medical; serving on the advisory board without compensation for Abbott, Biosense Webster Inc, Boston Scientific Corp, CardioFocus, Medtronic Inc, Boston Scientific Medical, Spectrum Dynamics, Siemens, Thermedical, Johnson & Johnson, and SigNum Preemptive Healthcare Inc; speaking with honorarium from Biotronik and MediaSphere Medical LLC; and receiving royalties from Wiley & Sons, Oxford, and St Jude Medical. Dr Packer and Mayo Clinic jointly have equity in a privately held company, External Beam Ablation Medical Devices, outside the submitted work. Dr Packer has mapping technologies with royalties paid. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
Funding Information:
Funding sources: This study was funded by Thermedical. Dr Packer’s work is funded in part by a clinician investigator award from the Mayo Foundation .
Publisher Copyright:
© 2020 Heart Rhythm Society
PY - 2021/3
Y1 - 2021/3
N2 - Background: Irrigated needle catheter ablation is efficacious for creation of transmural lesions in the left ventricle (LV). However, interdependence of needle orientation and myocardial fiber orientation and the resulting influence on lesion creation remain unclear. Objective: The purpose of this study was to investigate the impact of myocardial fiber orientation on reproducibility and controllability of lesion creation in LV myocardium using a heated saline-enhanced radiofrequency (SERF) needle-tip catheter system. Methods: Eleven dogs underwent catheter ablation using this novel catheter. Ablative lesions were created using different power and ablation times (15–50 W; application 25–120 seconds; 60°C irrigation saline at 10 mL/min). Hearts were explanted, and lesions were evaluated using 3-T cardiac magnetic resonance (CMR), gross pathologic, and histologic investigations. Results: Forty-three of 57 lesions (75.4%) were transmural, and lesion depth reached approximately 90% of LV wall thickness. Lesion volume in both gross pathology and ex vivo CMR showed a positive linear correlation with power × radiofrequency (RF) time index (r = 0.637, P <.001; and r = 0.786, P <.001, respectively). Maximum width (circumferential direction of LV) and maximum length (long-axis direction) of all lesions were distributed in the middle layer of LV where myocardium runs circumferentially. Paired-sample t-test showed maximum lesion width was significantly greater than maximum lesion length by both CMR and gross pathologic evaluation (26.1 ± 9.6 mm vs 17.2 ± 6.7 mm, P <.001; and 22.5 ± 7.7 mm vs 18.6 ± 5.9 mm, P <.001, respectively). Conclusion: This catheter showed feasibility in creating transmural LV lesions. Power × RF time index was strongly correlated with lesion volume and predicted lesion size. More importantly, SERF lesions extended along the myocardial fiber orientation.
AB - Background: Irrigated needle catheter ablation is efficacious for creation of transmural lesions in the left ventricle (LV). However, interdependence of needle orientation and myocardial fiber orientation and the resulting influence on lesion creation remain unclear. Objective: The purpose of this study was to investigate the impact of myocardial fiber orientation on reproducibility and controllability of lesion creation in LV myocardium using a heated saline-enhanced radiofrequency (SERF) needle-tip catheter system. Methods: Eleven dogs underwent catheter ablation using this novel catheter. Ablative lesions were created using different power and ablation times (15–50 W; application 25–120 seconds; 60°C irrigation saline at 10 mL/min). Hearts were explanted, and lesions were evaluated using 3-T cardiac magnetic resonance (CMR), gross pathologic, and histologic investigations. Results: Forty-three of 57 lesions (75.4%) were transmural, and lesion depth reached approximately 90% of LV wall thickness. Lesion volume in both gross pathology and ex vivo CMR showed a positive linear correlation with power × radiofrequency (RF) time index (r = 0.637, P <.001; and r = 0.786, P <.001, respectively). Maximum width (circumferential direction of LV) and maximum length (long-axis direction) of all lesions were distributed in the middle layer of LV where myocardium runs circumferentially. Paired-sample t-test showed maximum lesion width was significantly greater than maximum lesion length by both CMR and gross pathologic evaluation (26.1 ± 9.6 mm vs 17.2 ± 6.7 mm, P <.001; and 22.5 ± 7.7 mm vs 18.6 ± 5.9 mm, P <.001, respectively). Conclusion: This catheter showed feasibility in creating transmural LV lesions. Power × RF time index was strongly correlated with lesion volume and predicted lesion size. More importantly, SERF lesions extended along the myocardial fiber orientation.
KW - Catheter ablation
KW - Intramural ventricular substrate
KW - Irrigation needle catheter
KW - Transmural lesion
KW - Ventricular tachycardia
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U2 - 10.1016/j.hrthm.2020.11.015
DO - 10.1016/j.hrthm.2020.11.015
M3 - Article
C2 - 33212248
AN - SCOPUS:85101071885
SN - 1547-5271
VL - 18
SP - 443
EP - 452
JO - Heart rhythm
JF - Heart rhythm
IS - 3
ER -